mesenkymal

Mesenchymal, from mesenchyme, is a term used in biology and medicine to describe cells and tissues of embryonic origin derived from the mesenchyme, a loose, multipotent connective tissue in the mesoderm. In adults, mesenchymal cells contribute to the stroma of many organs and play roles in tissue repair and wound healing.

During embryogenesis, mesenchymal cells are multipotent and can differentiate into osteoblasts (bone), chondrocytes (cartilage), adipocytes (fat), and other stromal lineages, including muscle and vascular smooth muscle.

Mesenchymal stem/stromal cells (MSCs) are a widely studied subset. They are multipotent, capable of differentiating into osteoblasts, chondrocytes, and adipocytes in vitro. In culture they adhere to plastic and express surface markers CD105, CD73, and CD90, while lacking hematopoietic markers such as CD45, CD34, CD14 or CD11b, CD19 or CD79alpha, and HLA-DR. MSCs can be isolated from bone marrow, adipose tissue, umbilical cord tissue, dental pulp, and other tissues, and they possess immunomodulatory and anti-inflammatory properties.

In pathology and oncology, mesenchymal describes tissues of mesenchymal origin, such as connective tissue. Cancer biology also uses the term in reference to the epithelial-mesenchymal transition (EMT), a process whereby epithelial cells acquire mesenchymal traits, increasing motility and invasiveness.

Applications and considerations: MSCs are investigated for regenerative medicine and tissue engineering, including treatment of osteoarthritis, myocardial infarction, and graft-versus-host disease. While generally well tolerated, risks include infection, immune reactions, and, in some contexts, unwanted differentiation. Research aims to standardize definitions, isolation, and characterization to improve safety and efficacy.